[OCPBUGS-48096]: HCP proxy docs for mgmt clusters with secondary networks

Author: lahinson

hosted_control_planes/hcp-networking.adoc

@@ -18,6 +18,8 @@ include::modules/hcp-proxy-ignition.adoc[leveloffset=+1]
 include::modules/hcp-proxy-api.adoc[leveloffset=+1]
 //cp workloads that need access to external services and must use the proxy for the management cluster
 include::modules/hcp-proxy-mgmt-cluster.adoc[leveloffset=+1]
+//proxy configuration when the mgmt cluster has a second network and no default pod network
+include::modules/hcp-proxy-addl-network.adoc[leveloffset=+1]
 
 [role="_additional-resources"]
 [id="additional-resources_{context}"]

modules/hcp-proxy-addl-network.adoc

@@ -0,0 +1,9 @@
+// Module included in the following assemblies:
+//
+// * hosted_control_planes/hcp-networking.adoc
+
+:_mod-docs-content-type: CONCEPT
+[id="hcp-proxy-addl-network_{context}"]
+= Management cluster with a secondary network and no default pod network
+
+If the management cluster uses a proxy configuration and you are configuring an additional network but you are not attaching the default pod network, you need to add the CIDR of the additional network to the `noProxy` section of the proxy configuration on the management cluster. Otherwise, the Kubernetes API server will route some API requests through the proxy. In the hosted cluster configuration, the CIDR of the additional network is automatically added to the `noProxy` section.